Advertisements
Advertisements
Question
A sample of 12 M Concentrated hydrochloric acid has a density 1.2 M gL-1 calculate the molality.
Advertisements
Solution
Given:
Molarity = 12 M HCl
density of solution = 1.2 g L-1
In 12 M HCl solution, there are 12 moles of HCl in 1 litre of the solution.
Molality = `"no of moles of solute"/"mass of solvent (in kg )"`
Calculate mass of water(solvent)
mass of 1 litre HCl solution = density × volume
= 1.2 × gmL-1 × 1000 mL = 1200 g
mass of HCl = no. of moles of HCl × molar mass of HCl
= 12 mol × 36.5 g mol-1
= 438 g.
mass of water = mass of HCl solution – mass of HCl
mass of water = 1200 – 438 = 762 g
molality(m) = `12/0.762` = 15.75 m
APPEARS IN
RELATED QUESTIONS
Define mole fraction.
The sum of all mole fraction for a mixture is always equal to ____________.
On adding a solute to a solvent having vapour pressure 0.80 atm, vapour pressure reduces to 0.60 atm. Mole fraction of solute is:
How many grams of concentrated nitric acid solution should be used to prepare 250 mL of 2.0M HNO3? The concentrated acid is 70% HNO3:
Define the following modes of expressing the concentration of a solution. Which of these modes are independent of temperature and why?
(iii) w/V (mass by volume percentage)
What is molarity of resulting solution obtained by mixing 8.5 L of 0.5 m urea solution and 500 ml of 2 m urea solution?
3.36 M sulphuric acid solution is 29% H2SO4 calculate the density of the solution.
Calculated the mole fraction of benzene in a solution containing 30% by mass of its is carbon tetrachloride
A 6.50 molal solution of KOH (aq.) has a density of 1.89 g cm−3. The molarity of the solution is ______ mol dm−3. (Round off to the Nearest Integer)
[Atomic masses: K: 39.0 u; O: 16.0 u; H: 1.0 u]
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
